package org.qi4j.library.rest.client;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import org.junit.BeforeClass;
import org.junit.Test;
import org.qi4j.bootstrap.AssemblyException;
import org.qi4j.bootstrap.ModuleAssembly;
import org.qi4j.library.rest.client.api.ContextResourceClient;
import org.qi4j.library.rest.client.api.ContextResourceClientFactory;
import org.qi4j.library.rest.client.api.ErrorHandler;
import org.qi4j.library.rest.client.api.HandlerCommand;
import org.qi4j.library.rest.client.spi.ResponseHandler;
import org.qi4j.library.rest.client.spi.ResponseReader;
import org.qi4j.library.rest.client.spi.ResultHandler;
import org.qi4j.library.rest.common.ValueAssembler;
import org.qi4j.test.AbstractQi4jTest;
import org.qi4j.valueserialization.orgjson.OrgJsonValueSerializationAssembler;
import org.restlet.Client;
import org.restlet.Response;
import org.restlet.data.Protocol;
import org.restlet.data.Reference;
import org.restlet.resource.ResourceException;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import static org.qi4j.library.rest.client.api.HandlerCommand.refresh;
import static org.qi4j.test.util.Assume.assumeConnectivity;
/**
* Reads Qi4j Github commits on develop ATOM feed and prints out all title and detail url for each entry.
* This is an example of how to use the RSS client for something more generic that was not produced by Qi4j REST server
* library.
*/
public class RssReaderTest
extends AbstractQi4jTest
{
@BeforeClass
public static void beforeRssReaderTest()
{
assumeConnectivity( "github.com", 443 );
}
private ContextResourceClient crc;
@Override
public void assemble( ModuleAssembly module )
throws AssemblyException
{
// General setup of client
new OrgJsonValueSerializationAssembler().assemble( module );
new ClientAssembler().assemble( module );
new ValueAssembler().assemble( module );
}
@Test
public void testReadRssFeed()
{
Client client = new Client( Protocol.HTTPS );
Reference ref = new Reference( "https://github.com/Qi4j/qi4j-sdk/commits/develop.atom" );
ContextResourceClientFactory contextResourceClientFactory = module.newObject( ContextResourceClientFactory.class, client );
contextResourceClientFactory.registerResponseReader( new ResponseReader()
{
@Override
public Object readResponse( Response response, Class<?> resultType )
throws ResourceException
{
if( resultType.equals( Document.class ) )
{
try
{
DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
documentBuilderFactory.setNamespaceAware( false );
return documentBuilderFactory.newDocumentBuilder().parse( response.getEntity().getStream() );
}
catch( Exception e )
{
throw new ResourceException( e );
}
}
return null;
}
} );
contextResourceClientFactory.setErrorHandler( new ErrorHandler().onError( ErrorHandler.RECOVERABLE_ERROR, new ResponseHandler()
{
@Override
public HandlerCommand handleResponse( Response response, ContextResourceClient client )
{
System.out.println( ">> REFRESH on recoverable error: " + response.getStatus() );
return refresh();
}
} ) );
crc = contextResourceClientFactory.newClient( ref );
crc.onResource( new ResultHandler<Document>()
{
Iterator<Node> itemNodes;
@Override
public HandlerCommand handleResult( Document result, ContextResourceClient client )
{
try
{
final XPath xPath = XPathFactory.newInstance().newXPath();
System.out.println( "== " + xPath.evaluate( "feed/title", result ) + " ==" );
final NodeList nodes = (NodeList) xPath.evaluate( "feed/entry", result, XPathConstants.NODESET );
List<Node> items = new ArrayList<>();
for( int i = 0; i < nodes.getLength(); i++ )
{
items.add( nodes.item( i ) );
}
itemNodes = items.iterator();
return processEntry( xPath );
}
catch( XPathExpressionException e )
{
throw new ResourceException( e );
}
}
private HandlerCommand processEntry( final XPath xPath )
throws XPathExpressionException
{
if( !itemNodes.hasNext() )
{
return null;
}
Node item = itemNodes.next();
String title = xPath.evaluate( "title", item );
String detailUrl = xPath.evaluate( "link/@href", item );
System.out.println( "-- " + title + " --" );
System.out.println( "-- " + detailUrl + " --" );
return processEntry( xPath );
}
} );
crc.start();
}
}